This invention relates generally to gas ranges for home cooking and more particularly to upshot gas burner assemblies for gas ranges.
An upshot gas burner assembly for a gas range typically includes a base on the range top, a burner body beneath the range top in communication with a gas supply line for delivering gas to the burner, an orifice in the body for ejecting a metered amount of gas upwardly, a venturi above the orifice for receiving gas from the orifice and mixing it with air to form a gas-air mixture, a ported burner head overlying the venturi on the range top for discharging the gas-air mixture in a generally radially fingered pattern, and an igniter for igniting the gas-air mixture to produce a cooking flame. In many traditional burners, the base and the body are formed from a single piece of cast metal with a central opening, the body extending through an opening in the range top into the space below and the base resting on the range top. The gas line and orifice then connect to the base below the range top and a separate venturi mounts within the central opening. The base is secured to the range top with appropriate fasteners, such as screws. In many cases, adjustable vents or shutters or venturi position adjustments are provided for controlling the flow of air into the venturi to adjust the gas-air mixture ratios in the venturi. While such designs are functional, they nevertheless are relatively complex to assemble and even more troublesome to disassemble for cleaning and maintenance.
Many prior upshot burners also have included multi-piece venturi assemblies that include adjustments for regulating the gas-air mixture in the venturi. A set screw usually is provided for fixing the position of the adjustable portion of the venturi or an associated air regulation shutter when proper adjustment is obtained. The adjustability of the venturi in traditional burners is problematic because, among other things, it requires a relatively complex adjustment mechanism, is not easily removable for cleaning or maintenance, usually requires re-adjustment after removal, and is prone to being improperly adjusted, resulting in inefficient combustion in the cooking flame.
Accordingly, a need exists for an upshot burner for a gas range that provides for convenient removal and replacement of the venturi from the top without removing or raising the top tray of the range, convenient replacement of the gas orifice from the top without removal of the top tray, and easy and convenient cleaning of the burner base, ring, and cap. A burner that provides proper gas-air mixture within the venturi for efficient combustion under a wide range of conditions without the need for a multi-piece or adjustable venturi assembly is needed as is a burner that produces a stable flame and uniform distribution of heat over the heated area. Complete combustion, high flame controllability, quiet operation at all times, ease of ignition, and the ability to operate with a variety of gas compositions and pressures is desired. It is to the provision of a burner that meets these and other needs that the present invention is primarily directed.
Briefly described, the present invention, in a preferred embodiment thereof, comprises an upshot gas burner for a cooking range. The burner has a disc-shaped base that rests on the range top. The base has a central opening that aligns with a corresponding opening in the range top. A burner body has a generally cylindrical upper section that extends upwardly through the aligned openings in the range top and base to a threaded top rim. The body also is formed with a generally L-shaped hollow arm that depends from the upper section. The L-shaped arm has a threaded seat into which a gas orifice is threaded. The orifice, when threaded into the port, is centrally disposed beneath the cylindrical upper section. A gas supply line couples to the end of the arm to supply gas to the orifice, which is oriented to eject a metered flow of gas in an upward direction.
A single piece venturi has an elongated venturi tube with a lower end and an upper end. The upper end of the venturi is formed with a radially projecting annular flange that includes an internally threaded annular recess on its bottom side. The recess is sized to receive the threaded top rim of the cylindrical upper section of the burner body with the internal threads of the recess engaging the threads on the top rim of the body. With this arrangement, the burner may be mounted easily in the range top by moving the top section of the body upwardly through the aligned openings in the range top and base, inserting the venturi tube through the cylindrical upper section of the body, and threading the annular flange of the venturi tightly onto the top rim of the body. A burner ring and burner cap are then positioned on the base overlying the exit opening of the venturi tube to complete the assembly of the burner. To remove the venturi for cleaning, maintenance, or replacement, the burner ring and cap are removed and the venturi is simply unthreaded and removed from the base, all without removing or raising the range top itself. Further, with the venturi removed, the gas orifice is easily accessible through the top section of the body and can be removed for cleaning or replacement with a socket, again without removing or raising the range top.
The venturi tube of the venturi is carefully sized and configured such that, when the burner is mounted in the range top as described, the bottom end of the venturi tube is positioned at the appropriate distance above the gas orifice. This distance is predetermined to insure that the proper volume of air is drawn into the venturi tube with the gas flow, where it is mixed with the gas in the appropriate mixture for complete and efficient combustion under a variety of gas composition and line pressure conditions.
Thus, an upshot gas burner for a cooking range is now provided that successfully addresses the problems and shortcomings of traditional burners. The burner is easily installed in a range top and the venturi and orifice may be removed quickly and easily from the top for cleaning or replacement. Due to the careful positioning and-configuration of the single piece venturi tube, the gas-air mixture is optimized for a wide variety of conditions without the need for any venturi adjustment mechanism or movable shutters. Accordingly, the venturi tube is fixed and not subject to mis-adjustment as in the prior art. The burner produces a stable flame that is easily ignited, provides uniform heat, and operates quietly at all flame intensities. These and other features, objects, and advantages of the burner of this invention will become more apparent upon review of the detailed description set forth below, when taken in conjunction with the accompanying drawing figures, which are briefly described as follows.